Apparatus for foaming beer



Dec. 8, 1959 R Y 2,916,266

APPARATUS FOR FOAMING BEER Filed May 1, 1956 2 Sheets-Sheet l FIG.4.

G OUTPUT 35 36 37 TRANSFORMER GENERATOR I I OUTPUT I l 1 VARIABLE BUFFEROUTPUT FREQUENCY AND DRIVER AMPL'HER R.C.O5CILLATOR AMPLIFIER J ITRANSDUCER 38 k x I R.F. BYPAS5\ I 39 4 4: ll: T

1 4g' REGULATED VARIABL E o.c. FIELD LOW VOLTAGE HIGH VOLTAGE SuppSUPPLY SUPPLY v INVENT OR G. EMERSON PRAY n5 V.A.C.

so CYCLES HIS ATTORNEYS Dec 8, 1959 G. E. PRAY 2,916,266

APPARATUS FOR FOAMING BEER Filed May 1, 1956 2 Sheets-SheetZ 4 INVENTORG. EMERSON PRAY UM ZLQZ M HIS ATTORNEYS United States Patent APPARATUSFOR FOANIING BEER George Emerson Pray, Plainfield, N.,l., assignor, bymesne assignments, to Electronic Assistance Corporation, Red Bank, N.J.,a corporation of New York Application May "1, 1956, Serial No. 581,887

4 Claims. (Cl. 259-54) This invention relates to apparatus for inducingfoaming of liquids, and it relates particularly to apparatus by means ofwhich a quick and controlled foaming of beer and other gas-containing orcarbonated beverages can be produced.

In the production of beverages of the kind indicated, it is necessary toremove air from the bottles or other containers before sealing in orderto increase the shelf life of the beverage. The air is commonlydisplaced by causing the beverage to foam. Inasmuch as high productionrates must be achieved, the beverage must be caused to foam very quicklywithout, however, causing excessive overflow of the beverage from thecontainers.

Foaming can be produced by applying vibratory energy to the bottle orother container, using suflicient power to cause adequate foaming. Ifthis is done within the audible frequency range, the required powerlevel is so great as to be very objectionable and impractical from theoperators point of view.

In the brewing industry, foaming of beer is commonly produced bysubjecting the filled, but uncapped bottles or cans to impact by meansof a knocker or hammer. When the impact is hard enough to cause the beerto foam, it frequently breaks imperfect bottles, or causes varyingamounts of foam to be produced, thereby displacing the liquid unequallywith consequent variation in the contents of the containers. Whenbottles are broken, the bottling machine must be shut down to clear thebroken glass. Inasmuch as bottling machines operate at the rate of 200to 300 bottles per minute, even short shut-downs cause marked reductionin output.

I have discovered that by employing ultrasonic frequencies, that is,frequencies above the audible range, to vibrate the beverage in thecontainers, the etficiency of energy transfer through the container isimproved, the accelerating force applied to the liquid is greatlyincreased, and uniformity of foaming is achieved.

These results are obtained by means of an electronic generator whichsupplies alternating current power at a frequency of the order of 20kilocycles per second to an ultrasonic transducer which converts theelectrical energy into mechanical vibrations and applies it to thebottle or other beverage container. The vibrations are transmitted tothe liquid to release the gas therein in the form of bubbles or foam andthereby displace the air from the neck or top of the bottle or othercontainer.

The transducer is associated with the filling or bottling machine sothat the foaming is produced immediately following filling or bottling.High production rates can be maintained by arranging the transducer sothat it applies vibrations to the containers over a path equal in lengthto several times the diameter of the containers.

Close regulation of the power of the vibrations can be obtained bycontrolling the power supplied to the transducer so that there is littlevariation in the amount of foam produced in successive containers.Moreover, the vibrations are of small amplitude so that while asubstantial amount of energy is transmitted to containers, there islittle or no possibility of breakage of containers even if they areformed of glass of quite irregular thickness and strength. i

2,916,266 Patented Dec, 8, 1959 ICC For a better understanding of thepresent invention, reference may be had to the accompanying drawing inwhich:

Figure 1 is a perspective view of an apparatus for foaming beverages inaccordance with the present invention, the transducer of the apparatusbeing shown as positioned adjacent to the conveyor carrying bottlesafter filling;

Figure 2 is a plan view of the transducer of the apparatus with aportion of the casing therefor removed to disclose details thereof;

Figure 3 is a view in section taken on line 33 of Figure 2; and

Figure 4 is a schematic wiring diagram of the power supply andtransducer.

The apparatus chosen for purposes of illustration includes two units,namely, an ultrasonic generator G and a transducer T by means of whichvibrations of ultrasonic frequency can be imparted to the beveragecontainers and the beverage therein. The generator may be any well-knowntype including a variable frequency oscillator for generating a signalin the ultrasonic range, for example, of between about 15 kc. and 35 kc.and an amplifier to supply suflicient energy to the transducer toproduce foaming. In practice, a power output of watts is adequate toenergize several transducers.

The electronic generator G is housed in a cabinet 10 which is providedwith a door 11 giving access to the controls of the generator for tuningand regulating its power output. A window 11a is provided in the door 11to enable the voltmeter V and ammeter A in the front panel to beobserved. The cabinet 10 and door 11 are provided with gaskets and sealsto render the unit water tight inasmuch as it may be used in a wet ormoist environment.

Bottles B are carried through the bottling machine by means of holdingmembers 12 or saddles and the transducer T which has an elongated shoeor contact member 13 is positioned so that it is pressed resilientlyagainst the bottles as they are moved rapidly by it. The shoe 13 is longenough to engage two bottles simultaneously. Inasmuch as the shoe 13 isin contact with the surfaces of the bottles which may be wet due tooverflow while filling and foaming, the shoe is formed of a strip ofcorrosion-resistant material such as stainless steel. As best shown inFigure 2, the ends of the shoe are curved to enable the bottles to slideby them. To allow the shoe to engage bottles of varying diameter andassure good contact with the bottles, the shoe 13 is biased toward thebottles by moderate spring pressure. A suitable supporting and biasingstructure may include a pair of rods 14 and 15 fixed to the back of theshoe and slidably received in U-shaped brackets 16 and 17 extendinginwardly from and fixed to the ends of a casing 18 formed of stainlesssteel or other corrosion-re sistant material. Springs 19 and 20 aremounted on the rods and engage the back of the shoe 13 and the brackets16 and 17 to normally urge the shoe outwardly to the limit permitted bythe cross pins 21 and 22 in the inner ends of the shafts 16 and 17. Aremovable cover (not shown) is provided for the casing 18 and is securedto the flanges 24, 25 and 26 at the open side of the casing.

Vibration at ultrasonic frequency is imparted to the shoe 13 by amagnetostrictive vibrator which includes a core 27 formed of a pluralityof thin strips or laminations 28 of nickel or nickel alloy havingmagneto-strictive properties. See chapter IX, Magnetostriction inUltrasonics, by Carlin, published by McGraw-Hill Book Company, Inc.,1949. The laminations are welded, silver soldered or brazed at one endto the mid-portion of the shoe 13 and are supported by the shoe 13. Asshown in Figure 3, the core 27 has a centrally located hole 29 throughwhich the turns of coils 30 and 31 pass, each coil being wound on a legof the core at each side of the hole. One of the coils is woundclockwise and the other is wound counter-clockwise and they are joinedat their adjacent ends. A plastic insulated wire, such as a strandedNylon covered wire is used for the coils in order to render themwaterproof.

A magnetostrictive vibrator of the type described having a total of 80turns in the coils has a resonant frequency in the vicinity of 20 kc.When the generator G is tuned to produce a frequency corresponding tothe resonant frequency of the vibrator, maximum etficiency is obtained.For example, the dimensional changes in nickel are on the order of 25-30parts per million at frequencies other than the resonant frequency ofthe vibrator, while at resonance, the change may be as high as one partper thousand. Moreover, in accordance with recognized principles of suchvibrators, a DC. biasing field should be provided so that the core 27can be operated over a wide portion of its magnetization curve resultingin maximum amplitude of oscillation without overheating or causingfatigue of the metal.

A typical transducer T constructed as described above has an impedanceof about 16 ohms with a polarizing DC. of approximately one ampere whichis supplied together with the ultrasonic signal by the generator G. Thevibration of the shoe is produced essentially by reaction, i.e., as thefreely suspended core expands and contracts, it sets up oppositelyacting forces which cause almost imperceptible vibration of the shoe 13.

As shown in Figure 4, the ultrasonic generator G supplies a signal atultrasonic frequency by means of a variable frequency oscillator 35provided with an appropriate tuning condenser and a non-linear ballastresistance. The signal emanating from the oscillator is amplified in abuffer amplifier and driver amplifier 36 and then in a push-pull outputamplifier 37. The output of the amplifier 37 is supplied to an outputtransformer 38 connected to the transducer T. A conventional low voltagesupply 39 is connected to and energizes the oscillator 35 and the bufferand driver amplifier 36, and a variable high voltage supply 40 suppliesthe output amplifier 37 and enables the output of the generator to beregulated as required. A single transducer T of the kind describedrequires 20 to 25 watts to drive it so that a generator having an outputof 100 to 125 watts will supply several transducers and allow forsubstantial overload.

Direct current for supplying biasing voltage to the transducer isprovided by the DC. field supply 41 which includes a full Wave rectifierbridge and a condenser 42 to by-pass the radio frequency signal. Currentis supplied to the rectifier bridge from the filament supply of theoscillator at about 6.3 volts.

With the generator and transducer in operation and the output of thegenerator supplying a signal at about the resonant frequency of thetransducer, an almost imperceptible vibration of the shoe 13 occurs,that is, a vibration of an amplitude of only a few thousandths of aninch. However, a very substantial amount of power is supplied by thevibration of the shoe. When containers of beverage move along in contactwith the shoe, the beverage foams almost instantly so that the air abovethe beverage in the container is displaced. Inasmuch as the powersupplied to the shoe 13 is constant and the shoe is pressed against eachcontainer with essentially the same force, foaming is uniform in thecontainers as they pass by the transducer T even at rates of about 200to 300 per minute.

Breakage of bottles is completely avoided by the new apparatus for thereason that the amplitude of the vibrations is insufficient to flex thecontainer beyond its breaking point even with non-uniform and poorlyannealed glass.

It will be understood that the generator G may be modified as to typeand power output, and that the length and shape of the shoe of thetransducer and the manner in which it is mounted may be altered.

Accordingly, it will be understood that the foamproducing apparatusdescribed herein is illustrative of the invention and is susceptible toconsiderable modification in its design and in structure withoutdeparting from the invention.

I claim:

1. An apparatus for foaming beverages in open top containers comprisingconveying means adapted to move open top containers having agas-containing beverage therein along a path, a casing adjacent to saidpath, a pair of rods slidably mounted in substantially parallel relationin said casing, a shoe mounted on said rods for movement toward and awayfrom said casing and overlying a portion of said path thus adapting saidshoe to engage any containers moving along said path, spring meansinterposed between said shoe and said casing biasing said rods and saidshoe outwardly for engagement with containers moving along said path,and a reaction type ultrasonic vibrator mounted on and movable with saidshoe and disposed in said casing for vibrating said shoe at ultrasonicfrequency to vibrate said containers and cause the beverage therein tofoam.

2. The apparatus set forth in claim 1 in which said vibrator is amagnetostrictive vibrator having a core of magnetostrictive materialfixed to and supported by said shoe and a coil wound on said core.

3. An apparatus for causing foaming of beverages in open containers todisplace air therefrom comprising conveying means adapted to move opentop containers of beverage along a path, a transducer adjacent to saidconveying means having a shoe overlying a portion of said path, meansfor supporting said shoe for movement toward and away from said path,resilient means biasing said shoe toward said path for resilientengagement against any container moving along the path, an elongatedmagnetostrictive core member having a resonant frequency in theultrasonic range fixed at one end to said shoe and supported thereby, acoil encircling said core member for energization by an electricalsignal to expand and contract said core member and vibrate said shoe byreaction, and power supply means connected to said coil for supplying asignal at about the resonant frequency of said core member to vibratesaid shoe at ultrasonic frequency.

4. An apparatus for foaming beverages in open top containers comprisingconveying means adapted to move open top containers having agas-containing beverage therein along a path, a casing, a shoe at oneside of said casing overlying a portion of said path and adapted tocontact any container moving along said path, means in said casingsupporting said shoe for movement inwardly and outwardly relative tosaid casing, resilient means interposed between said casing and saidshoe for resiliently urging said shoe outwardly relative to said casingfor contact with said containers moving along said path, a core ofmagnetostrictive material fixed at one end to said shoe and supportedthereby, and a coil encircling said core to magnetize and demagnetizesaid core and thereby change its length for vibrating said shoe relativeto said casing and the containers in contact with said shoe to causesaid beverage to foam.

References Cited in the file of this patent UNITED STATES PATENTS1,820,676 Pickop Aug. 25, 1931 2,114,964 MacKenzie Apr. 19, 19382,119,174 Nicolas May 3, 1938 2,237,636 Schmutzer Apr. 8, 1941 2,341,498Bell Feb. 8, 1944 2,498,990 Fryklund Feb. 28, 1950 2,620,894 Peterson etal. Dec. 9, 1952 2,660,414 Von Ludwig Nov. 24, 1953 2,815,193 Brown Dec.3, 1957

